title: Inhibition of AMPK and Krebs cycle gene expression drives metabolic remodeling of Pten-deficient preneoplastic thyroid cells.
abstract: Rapidly proliferating and neoplastically transformed cells generate the energy required to support rapid cell division by increasing glycolysis and decreasing flux through the oxidative phosphorylation (OXPHOS) pathway, usually without alterations in mitochondrial function. In contrast, little is known of the metabolic alterations, if any, which occur in cells harboring mutations that prime their neoplastic transformation. To address this question, we used a Pten-deficient mouse model to examine thyroid cells where a mild hyperplasia progresses slowly to follicular thyroid carcinoma. Using this model, we report that constitutive phosphoinositide 3-kinase (PI3K) activation caused by PTEN deficiency in nontransformed thyrocytes results in a global downregulation of Krebs cycle and OXPHOS gene expression, defective mitochondria, reduced respiration, and an enhancement in compensatory glycolysis. We found that this process does not involve any of the pathways classically associated with the Warburg effect. Moreover, this process was independent of proliferation but contributed directly to thyroid hyperplasia. Our findings define a novel metabolic switch to glycolysis driven by PI3K-dependent AMPK inactivation with a consequent repression in the expression of key metabolic transcription regulators.
authors.affiliation: Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Price Center for Genetic and Translational Medicine, 1301 Morris Park Avenue,Room 302, Bronx, NY 10461, USA. antonio.dicristofano@einstein.yu.edu
authors.forename: Valeria G
authors.initials: VG
authors.lastname: Antico Arciuch
authors.forename: Marika A
authors.initials: MA
authors.lastname: Russo
authors.forename: Kristy S
authors.initials: KS
authors.lastname: Kang
authors.forename: Antonio
authors.initials: A
authors.lastname: Di Cristofano
mesh_terms: D055372:AMP-Activated Protein Kinases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D015153:Blotting, Western; D049109:Cell Proliferation / Q000187:drug effects; D019069:Cell Respiration; D002478:Cells, Cultured; D002952:Citric Acid Cycle / Q000235:genetics*; D015180:Electrophoresis, Gel, Two-Dimensional; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005434:Flow Cytometry; D006019:Glycolysis; D047468:Immunoprecipitation; D007773:Lactates / Q000378:metabolism; D008156:Luciferases / Q000378:metabolism; D053078:Membrane Potential, Mitochondrial; D051379:Mice; D018345:Mice, Knockout; D046529:Microscopy, Electron, Transmission; D008928:Mitochondria / Q000378:metabolism; D010085:Oxidative Phosphorylation; D010101:Oxygen Consumption; D051059:PTEN Phosphohydrolase / Q000502:physiology*; D019869:Phosphatidylinositol 3-Kinases / Q000235:genetics / Q000378:metabolism; D000081082:Phosphoinositide-3 Kinase Inhibitors; D011230:Precancerous Conditions / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D040901:Proteomics; D051057:Proto-Oncogene Proteins c-akt / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics; D034741:RNA, Small Interfering / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013961:Thyroid Gland / Q000378:metabolism*; D013964:Thyroid Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*
chemical_list: D055372:AMP-Activated Protein Kinases; D004791:Enzyme Inhibitors; D007773:Lactates; D008156:Luciferases; D051059:PTEN Phosphohydrolase; D019869:Phosphatidylinositol 3-Kinases; D000081082:Phosphoinositide-3 Kinase Inhibitors; D051057:Proto-Oncogene Proteins c-akt; D012333:RNA, Messenger; D034741:RNA, Small Interfering; C487757:Pten protein, mouse